canvas实现粒子碰撞消失动画效果代码

代码语言:html

所属分类:动画

代码描述:canvas实现粒子碰撞消失动画效果代码

代码标签: canvas 粒子 碰撞 消失 动画

下面为部分代码预览,完整代码请点击下载或在bfwstudio webide中打开

<!DOCTYPE html>
<html lang="en" >

<head>
  <meta charset="UTF-8">
  

  
  
<style>
body {
  font-family: Arial, Helvetica, "Liberation Sans", FreeSans, sans-serif;
  background-color: #000;
  margin: 0;
  padding: 0;
  border-width: 0;
  overflow: hidden;
  cursor: pointer;
}
</style>


</head>

<body>

  
      <script >
"use strict";

window.addEventListener("load", function () {
  let canv, ctx; // canvas and context
  let maxx, maxy; // canvas dimensions

  const NUM_ATOMS = 500; // base to calculate number of atoms. Actual number may differ
  const DIAMETER_RATIO = 0.6; // ratio particle diameter / distance between particle centers
  const REL_PHOTON_SPEED = 10; // speed in aDist / second
  const EMISSIVITY = 1.5; // average number of photons emitted during disintegration
  const PHOTON_TRAIL = 3; // in aDist;
  const DISAPPEAR_TIME = 1000; // average time for atom disappearance

  let aDist, aRadius; // actual distance between atoms centers, actual radius
  let pRadius; // radius of emited particle

  let pSpeed; // actual REL_PART_SPEED converted in pix / ms
  let pTrail; // actual PHOTON_TRAIL converted in pixels
  let tTrail;
  let numExploding;

  let nbx, nby;
  let offsX, offsY;
  let crystal, photons;

  // for animation
  let messages;

  // shortcuts for Math.
  const mrandom = Math.random;
  const mfloor = Math.floor;
  const mround = Math.round;
  const mceil = Math.ceil;
  const mabs = Math.abs;
  const mmin = Math.min;
  const mmax = Math.max;

  const mPI = Math.PI;
  const mPIS2 = Math.PI / 2;
  const mPIS3 = Math.PI / 3;
  const m2PI = Math.PI * 2;
  const m2PIS3 = Math.PI * 2 / 3;
  const msin = Math.sin;
  const mcos = Math.cos;
  const matan2 = Math.atan2;

  const mhypot = Math.hypot;
  const msqrt = Math.sqrt;

  //------------------------------------------------------------------------

  function alea(mini, maxi) {
    // random number in given range
    if (typeof maxi == "undefined") return mini * mrandom(); // range 0..mini
    return mini + mrandom() * (maxi - mini); // range mini..maxi
  }
  // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  function intAlea(mini, maxi) {
    // random integer in given range (mini..maxi - 1 or 0..mini - 1)
    //
    if (typeof maxi == "undefined") return mfloor(mini * mrandom()); // range 0..mini - 1
    return mini + mfloor(mrandom() * (maxi - mini)); // range mini .. maxi - 1
  }
  // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  function distance(p0, p1) {
    return mhypot(p1.x - p0.x, p1.y - p0.y);
  } // distance

  //------------------------------------------------------------------------
  class Photon {
    constructor(atom, t) {
      this.atom = atom;
      this.c = atom.c; // initial position
      this.p = Object.assign({}, atom.c); // current position
      this.pkx = atom.kx; // previous kx and ky
      this.pky = atom.ky;
      this.tInit = t;
      const angle = alea(m2PI);
      this.sin = msin(angle) * pSpeed;
      this.cos = mcos(angle) * pSpeed;
      this.animState = 0;
      this.color = `hsl(${atom.hue} 100% 50%)`;
      this.trailingColor = `hsl(${atom.hue} 60% 30%)`;
    } // constructor

    animate(t) {
      const dt = t - this.tInit;
      switch (this.animState) {
        case 0:
          this.p.x = this.c.x + this.cos * dt;
          this.p.y = this.c.y + this.sin * dt;
          let kx = mround((this.p.x - offsX) / aDist);
          let ky = mround((this.p.y - offsY) / aDist);
          if (kx == this.atom.kx && ky == this.atom.ky) return; // no suicide !

          let currDist;
          while (mabs(this.pkx - kx) + mabs(this.pky - ky) > 1) {
            // check all atoms between previous and present positions (may be far !)
            /* try to move 1 cell in X and Y directions, and keep closest */
            let d1, d2;
            let currC = crystal[this.pky][this.pkx];
            if (currDist === undefined) currDist = t.........完整代码请登录后点击上方下载按钮下载查看

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